We are renting a 70-year-old house. The toilet is on a septic tank and our water source is a well about 50 yards away. Everytime the toilet is flushed, it takes down everything except the toilet paper, which floats right back up. We've already used an auger, septic sytem cleaners that you pour down the toilet, and lots of plunging. Our house has very low water pressure, too. Any ideas about what we should do?